1. Field of the Invention
The present invention relates to a mobile terminal, and more particularly, to an apparatus and method for preventing lock-up of an LCD in a mobile terminal.
2. Background of the Related Art
In general, a liquid crystal display (LCD) is a device that utilizes an optical switching phenomenon. Specifically, liquid crystal, an intermediate between a solid and a liquid, is injected between two thin glass plates and the arrangement of the liquid crystal molecules can be changed by creating a voltage difference between electrodes on the upper and lower glass plates. In this way, the liquid crystal molecules can be rearranged to manipulate the polarization of input light, which in turn can be used to provide light and dark areas on a pixel-by-pixel basis in order to display a number or an image.
Once used for watches or electronic computers in the 1970's, the LCD's scope of use has since been extended and is now a core display device used for advanced information devices and image displayers.
Because LCDs are thin, light and exhibit low power consumption, they are suitable for portable information terminals, such as notebook computers (laptop computers) and mobile phones. The relative importance of LCDs for mobile phone applications is rising, and thus larger and more complicated LCDs are being made.
However, as LCDs become larger and more complicated, they become more susceptible to electrostatic discharge (ESD). Thus, a method for operating the LCD in a normal manner when it is locked up by the ESD of the mobile terminal is needed.
Related art methods for preventing lock-up of an LCD of a mobile terminal include a hardware method, in which a transient voltage suppression (TVS) diode, for preventing static electricity from being introduced, is installed at lines connected to each input pin of the LCD of a mobile terminal. Another related art method is a software method, in which the LCD is periodically reset by software.
FIG. 1 is a drawing illustrating an example of an apparatus for preventing lock-up of an LCD in a mobile phone, in accordance with the related art. As shown in FIG. 1, the related art apparatus for preventing lock-up of an LCD in a mobile phone includes: an LCD 10 for displaying an image; a baseband chip set 20 for controlling a display operation of the LCD 10; and first through sixth TVS diodes (TVS1–TVS6) for limiting each voltage input to the LCD 10.
The first TVS diode TVS1 limits a voltage input so as to be boosted in the LCD 10 and a brightness control voltage. The second TVS diode TVS2 limits a level of a data input from the baseband chip set 20 to the LCD 10. The third TVS diode TVS3 limits a level of a clock input from the baseband chip set 20 to the LCD 10. The fourth TVS diode TVS4 limits a level of an address input from the baseband chip set 20 to the LCD 10. The fifth TVS diode TVS5 limits a level of a chip select signal input from the baseband chip set 20 to the LCD 10. The sixth TVS diode TVS6 limits a level of a reset signal input from the baseband chip set 20 to the LCD 10.
In this manner, the related art LCD lock-up preventing apparatus using TVS diodes in the mobile terminal limits the voltage input to each pin of the LCD 10, thereby preventing the LCD 10 from being locked up due to the ESD. However, the related art LCD lock-up preventing apparatus that utilizes TVS diodes in the mobile terminal has disadvantages in that, since a TVS diode needs to be provided for every line input to each pin of the LCD, the size of the LCD is increased, which makes this approach unsuitable for mobile terminals, which are typically compact in size.
The software method for periodically resetting the LCD in order to prevent lock-up of the LCD causes inconvenience for users, as the LCD is periodically reset and thus blinks periodically.
The above references are incorporated by reference herein where appropriate for teachings of additional or alternative details, features and/or technical background.